1. Field of the Invention
This invention relates to fruit harvesting machines and more particularly to an automatic fruit picking machine for picking citrus fruits, such as oranges, grapefruit, or the like, from trees.
2. Description of the Prior Art
In the past, the picking of citrus fruits other than by hand and with aids such as cherry pickers has presented many problems because the fruit is very strongly held to the trees and thus takes considerable force to remove without damage to the fruit or to the trees.
Many approaches have been devised to remove citrus fruit by machine harvesting, but these have frequently been copied from harvesters used for other types of fruit, vegetables or nuts and herebefore have had only limited success. One approach has been to shake the tree with a mechanical shaker which grasps the tree trunk and rapidly shakes the fruit loose while a net of some type is used to catch the fruit that falls from the tree. Alternatively, the fruit can be allowed to fall to the ground where a windrowning machine can be used to gather the fruit from the ground. These type of devices have met with only limited success on those types of fruits that are more loosely held to the trees and can do considerable damage to the trees. Attempts have been made to find ascession chemicals to apply to the trees for loosening the fruit, but such chemicals have to date been expensive and have not always proven safe. Another approach has been to blow the fruit off the trees with big wind producing machines, but this approach has problems similar to the shaking mechanisms in that the trees are damaged by small limbs and the like being blown off the tree along with the fruit. Other prior art devices have tried raking the fruit off with long armed mechanical rakes moved through the trees in various manners in order to pull the fruit from the trees, but this method also results in damage to the trees by pulling small limbs therefrom and by bruising and scraping the fruit and limbs. One group of devices has used a large group of spindles or bores that are rotated and moved into the tree to cut or twist the fruit loose and various devices for cutting the limbs holding the fruit have been suggested as has the application of a DC voltage to the trees to loosen the fruit.
A typical prior art fruit harvesting machine can be seen in the Lasswell U.S. Pat. No. 3,222,855, for harvesting spindles having rotatable spindles for insertion into fruit trees and in the Tanner U.S. Pat. No. 3,483,687, for citrus fruit harvester having a plurality of spindle elements for insertion into the trees for breaking the fruit loose from the tree. A similar patent can be seen in the Pool U.S. Pat. No. 3,153,311 for a mobile fruit picker with rotating harvesting spindles. Another Lasswell U.S. Pat. No. 3,458,982 teaches a fruit picking spindle arrangement therefor for breaking the fruit from the trees by twisting the fruit with rotating spindles. Each of this group of prior patents illustrates a plurality of spindles or twisting members which are directed, points first, from the outer perimeter towards the center of the tree. In contrast, the present invention moves along a row of citrus trees, with a plurality of booms passing sideways through one side of each tree passed.
Additional prior art patents may be seen in a U.S. Pat. by Bartram No. 3,543,494, which teaches a fruit picker with a plurality of rotating screws for inserting and twisting fruit from a tree and in the Recker U.S. Pat. No. 3,527,039 which illustrates a fruit harvester including reciprocable and rotatable rod-like helical members. The Staats U.S. Pat. No. 3,475,888 has tines that engage the fruit in the tree and feed it into a rotating, twisting element for breaking the fruit and dropping it into a conveyor, and the McCray U.S. Pat. No. 3,427,796 has rotating picker heads which rotate in opposite directions for gripping and twisting the fruit free.